Two-cycle engine



Sept. 15, 1942. TOCE ET AL 2,295,978

TWO-CYCLE ENGINE Original Filed Au 23, 1941 s Sheets-Shee t 1 CHARLESATOGE VKZTO R I Toc E INVENTORfi BY 5% 6 M ATTORH E'Y.

Sept. 15, 1942. I 1 c TQCE AL 2,295,978

' TWO-CYCLE ENGINE Original Filed Aug. 25, 1941 3 Sheets-Sheet 2 CHARLESA TocE Vl CTO R T- TOCE 1NVENTOR5 BY V ofuih ATTORNEY.

p 15, 1942- c. A, TQCE Em 2,295,978

\ TWO-CYCLE ENGINE Original Filed Aug. 23, 1941 3 Sheets-Sheet 5 CHARLE5 TocE VICTOR 21'. Tom:

\ INVENTORD BY Q hmA Patented Sept. 15, 1942 TWO CYCLE ENGINE.

Charles-A. Toce and Victor J. Toce, Houston, Tex v assignorsto FederalAircraft Engine Corporation, HoustomTex.

; Original application August 23, 1941, Serial No. 408;030; now PatentNo. 2,278,038, dated March Divided and this application March 28; 1942;SerialNo. 436,682

4 Claims.

The inventionlrelatesto: a two-cycle internal combustion engine of thepre-comp'ression type and specifically includes an arrangement wherebycompressed air isfed'. into the cylinder to scavenge the cylinder andthe fuel thereafter injected into the combustion chamber.

This" application is a division of ourprior copending application,Serial 408,030, filed August 23, 1941, for a two cycle engine'whichhasmaturedinto Patent 2,278,038.;datedMarch 31, 1942, wherein the pistonand compression. head assembly, and the air compression and fuelinjection arrangements are claimed; whereas, in this application thebody parts and driving gearing arebeing claimed; l

With two cyc'l'e internal combustion engines various arrangements have.been provided heretofor'e for pre-co'in'pressing the explosive mixtureand for scavenging the cylinders. Considerable difiicul'ty has beenencounteredin these prior devices, however, because if the gaseousmixture forced into the combustion cylinder under pressure is to effecta complete scavenging of the combustion gases, it-seems obvious that apercentage 'of the incoming explosive mixture will pass on through theexhaust opening with the combustion gases, sothat therehas'beendifficult'y in designing an engine whereby satisfactoryscavenging could be obtained on the; one hand and the economical use offuelion the other hand. a

The present invention contemplates a solution of this problem bylire-compressing air from the atmosphere and" using this air as ascavenging medium and after this scavengingroperation has been completedand a body of this compressed air trapped in the combustion chamber,then. the fuel islin'jected' and the explosionpromoted; In this manner"it is not imperative that the arrangement of the engine be such thatthere be no escape of the incoming compressed air through the exhaustportybut, as: a matter of fact, some of the incoming air may pass outthe exhaust port in order'to. obtain a satisfactory scavenging. of .thecylinder.

It.is,.therefore, one ofthe objects; of the invention to" pre-compressair and use it in scavenging' atWo-cycle internal combustion engine andthen inject fuel intothe trapped: compressed air to obtain. an explosivemixture in'the combustion chamber.

Another object of the invention is to provide an assembly of partsmaking up the engine-body so that the combustion. and compression,chambersj will be in proper alignment.

Still another object of the invention is to pro- Vide particularlyshaped parts for the engine body so that they will support thecombustion cylinder and arotary-valve block or housing. Itis also anobject of. the invention to provide a cross bracing within the body soasto provide a bearing for the crank shaft to reinforce the side andbase portions of the body.

Still another object of the invention is to provide an engine having arotary precompression valve which is disposed for rotation below thecrank shaft.

Other and further objects of the invention will be readily apparent whenthe-following description is considered in connection with theaccompanying drawings, wherein:

Fig. 1 is a longitudinal vertical section thru an engine constructed inaccordance with the invention.

Figs. 2, 3, and 4 are transverse sections taken on the lines 2-2, 3--3and 44 respectively of Figil.

Fig. 5 is a vertical sectional view of the piston and compression unit.

Fig. 6 is a section taken on the line B-6 of Fig; 5. I

In Fig. 1 the body of the engine is illustrated at 2 and may be of anydesired type of construction which is arranged to support a crankshaft 3by means of theplurality of sets of bearings such as' 4. The presentform shows a twocylinder engine wherein the crankshaft has the throwportions 5 arranged" to receive the connecting rod 6 of each cylinder.The base portion 8 of the body is arranged with a compression cylinderS, which is best seen in Fig. 2, as having a port l0 controlled by therotary valve II. An inlet 12 into the valve is shown as being openedwhile the head moves up to permit the inlet of air to the chamber 9. Theoutlet I3 from the compression chamber is connected to the conduit [4which is, turn, connected into the combustion cylinder [5.

The valve It may be driven by the valve shaft [B from the gear train Hwhich is, in turn, driven by the gear I8 on the crankshaft 3. Suitableanti-friction bearings and the usual connections for such gearing havebeen provided.

The combustion cylinder I5, as seen in Fig. 2, has the" bypass 14arranged part way along the cylinder so as to provide for the inlet of'compressed air. The exhaust or outlet 20 is shown as being on theoppositeside from the inlet but it may be arranged otherwise if desired.The head of this cylinder contains openings 2| which The piston 25 is ofthe barrel type and has a particular construction in the form of asupporting rib 21' adjacent the lower end of the piston; This rib hasthe bosses 28 thereon, which are seen in Fig. 6 as being four in number.These bosses each receives a rod 30 which may be rigidly connected inthe boss in any desired manner. These rods are spaced circumferentiallyaround the piston on quarter-points, as seen in; Fig. 6, with a view ofstraddling the crankshaft 3 in one direction and allowing the operationof the throw 5 of the crank and its counterweight- 1 in a transversedirection. In other words, these rods straddle the crankshaft andsupport the compression :head 3| on their lowerends.

Thepompression head 3| is in the form o f 'a short piston which isarranged to reciprocate in the compression cylinder 9. In this mannerthe combustion cy nder and the compr s ion li der are diametricalwithregard to the crankshaft, as is readily apparent from Fi lli'This pistonand compression unit is ,a rigid assembly so that the compression andcombustioncylin clers are in direct alignment.

The head of the piston 25 has the bafiie'portion 33 thereon, as seen inFig. 2, same: the face tends to deflect the incoming'fcompres'sed airand cause it to circulate in the combustion chamber, while the oppositeface 35'allows1the opening of the exhaust port as the piston moves down.In this manner complet scavenging of the combustion cylinder isobtainedbecause the ports and the piston can be so'constructed andarranged'that the amount of compressed air to be fed into thecylindenwill'be sufficient to obtain complete'scavenging; o'fthecombustiongases. f This is true because the exhausting of some of thecompressed air along with the combustion gaseswill not aifect theeconomy of the engine as regards'fuel. :1 i

The righthaild 'sideiof Fig; 1 shows the usual mechanismifor'injectionof the fuel and operation of the felectric systems which are" well knownwith internal combustion engines and need not be here described indetail. I

In operationfasthe piston moves down to uncover the inlet connection l4,there will be an inflow of compressed air from the compression cylinder9. The Valve II will be so timed as to Openon' the downstroke ofthe'compression head at such 'tilme as to allow the compressed air tofeed'through the bypass 4 and enter thecombustioncylinder l5. The inletof the compressed air into the combustion cylinder scavenges thecombustion gases therefrom, driving them out the exhaust port 20.' Asthe piston 'reverses' its stroke and closes the inlet andoutletifvalves, there will be a body of compressed'air trapped in thecombustion cylinder. The pistonfmo've'sup to effect further compressionof'this air. At a suitable period in this operation the? desired amountof fuel will be injected into the compressed air so as to obtainan'explosive mixture. The ignition of this mixture will occur at theproper time to effect the explosion and power stroke of the engine.

During this upstroke operation the valve will open, as seen in Fig. 2,to permit the inletof air to the compression chamber, and this valvewill close on the downstroke so that the air in the chamber 9 and theby-pass M will be com pressed. The valve H is of such width that theinlet l2 and outlet I3 will never be interconnected. H

The construction of the body is such that it is made up of twocomplementary halves, the upper half 48 and the lower half 4| areconnected by the flanges 43 in any suitable manner. Thesetwo halves forma box like structure, the upper half having inclined side walls 44 and aflat wall area 45 closing what is shown as the top part 'in Fig. 2. InFig. 1 the ends of each half are closed by the end structure 46 while,on the other hand-the lower half 44 has the side walls 41 and the flatwall area 48 with the end structure at 49 as seen in Fig. 1.

The upper half has an opening 50 therein which is arranged to receivethe skirt portion 5| of the combustion cylinder 5 which projects intothe opening and is held in place by the bolts 52 which aflixes thecombustion cylinder to the wall area 45.

Extending along one of the walls 44 is the by-pass conduit l4 by whichthe compressed air moves into the combustion cylinder.

The lower half 44 has a compression cylinder sleeve 55 extendinginwardly from the wall area 48 and is arranged to carry the liner 58 inwhich the compression head 3| is arranged to reciprocate.

Connected to the lower wall area 48 is the crank case 58 which is seenin longitudinal section in Fig. 1. This crank case has the end brackets59 therein which carry the bearings 68 to support the rotary valvesleeve 6| This sleeve carries the rotor shaft l6 as seen in Fig. 2, sothat the shaft and the sleeve rotate as a unit.

This sleeve 6| has the outwardly extending flanges 62 thereon which arespaced apart by the wings 63 of the valve ll. These flanges 62 and thevalve rotate inside of a cylindrical liner 84 depending from the toparea of the crank case 58. The flanges 62 serve to form a seal at eitherend of the wing 63 so as to cause the inlet and outlet of air as thevalve I rotates. A clamp 65 can be used to maintain a tight fit of thesleeve 64 about the rotor.

A central bearing and a front bearing are also carried by the crank caseas is the other sleeve 64 for the next adjacent piston assembly. Thisrotor valve shaft is driven by the gear 18 which meshes with a drivengear 1| which is, in turn, connected to the drive gear 12 on the crankshaft 3. An oil pump gear 15 meshes with the reduction gear 18 so thatthe speed of the oil pump 11 will effect the desired circulation of oil.

Fig. 3 shows the contour of the crank case 58 at the forward end so asto accommodate the various gears.

Particular attention is directed to the internal construction of thehalves 48 and 4| as seen in Figs. 1, 2 and 3. Fig. 3 shows thetransverse partition 82 which tend to support the crank bearings 8| soas to prevent vibration. There is a similar rear end partition at 82 andan opposite end partition 83 at the other front end.

These baflies in turn are joined by longitudinal partitions 84, 85and'86 respectively. These longitudinal baiiles serve to brace thebearings and the compression sleeve 55 so that there will be little orno vibration of the bearings and the shaft and the pistons as well asthe compression heads will be kept in perfect alignment during operationof the engine.

Broadly the invention contemplates a particular construction of anengine body which can be readily manufactured and the parts quicklyassembled.

What is claimed is:

1. A two cycle internal combustion engine including a body composed ofupper and lower complementary halves, each half having tapered sidewalls joined by a flat Wall area, ends for each body half, each endhaving a crankshaft bearing receiving portion, the flat wall area havingan opening therein, and a combustion cylinder body projecting thru saidopening, an opening in the flat wall area of the other body half, aninwardly projecting sleeve defining said opening, a valve block oversaid opening and forming a compression chamber, a conduit from thecompression chamber thru the block, along a side wall of the bodyhalves, and into said combustion cylinder body, and means to connectsaid halves cylinder and block together as a unit.

2. In an internal combustion engine assembly having combustion andcompression chambers,

an engine body including a lower half, said half having inclined sideWalls spaced apart, a flat base portion connecting said walls, acompression chamber sleeve in said base, and a transverse baflleconnecting the side walls on opposite sides of said compression chamber.

3. In an internal combustion engine assembly having combustion andcompression chambers; an engine body including a lower half, said halfhaving inclined side walls spaced apart, a flat base portion connectingsaid walls, a compression chamber sleeve in said base, a transversebaffle connecting the side walls on opposite sides of said compressionchamber, and a longitudinal flange extending from said baffle at thecenter to support said sleeve.

4. In a two cycle internal combustion engine a body, a crank shafttherein, combustion and compression chambers carried by the body anddisposed on opposite sides of said shaft, a gear train driven by saidshaft, including a drive gear on the shaft, a driven gear therebelow, arotary valve gear which is in turn driven by said driven gear, and anoil pump gear driven by said valve gear whereby the rotary valve isdisposed below the crankshaft.

CHARLES A. TOCE. VICTOR J. TOCE.

